5 Signs You Need Furnace Repair

A furnace that is about to fail rarely does it quietly. It gets louder, runs longer, heats unevenly or starts to smell. Catching those changes early usually means a smaller repair, a lower fuel bill and a lot less stress when the temperature drops. Here are five signs worth acting on, and what is typically behind each one.

• Strange noises from the furnace
• Poor heating performance or hot and cold spots
• The furnace cycling on and off frequently
• Odd or unpleasant smells
• Fuel or energy use that is higher than normal

1. Strange noises

Different sounds point to different problems. A bang or boom when the burners light can come from dirty burners and delayed ignition, which lets gas build up before it lights. That is a reason to shut the furnace off and call a professional. Rattling or clanking usually means a loose part. Squealing, screeching or grinding often traces to a worn blower motor, belt or bearing. Whistling suggests an airflow restriction, such as a clogged filter, leaky ducts or blocked vents. A hum or buzz can mean an electrical problem, a failing capacitor or a motor that is struggling.

2. Poor heating performance

If the furnace runs but the house is slow to warm up, or some rooms stay cold, the cause is often one of a handful of things:

• A dirty air filter that forces the furnace to work harder to move air
• Blocked or leaky ducts, closed vents, or rugs and furniture blocking registers
• A thermostat that reads the wrong temperature or cycles the furnace improperly
• A blower motor that cannot move enough air
• A furnace that is too small for the house or nearing the end of its life

Start by replacing the filter and opening every register. If the problem continues, it is time for an inspection.

3. Frequent on and off cycling

Short cycling wastes energy and strains the system. A clogged filter can cause the furnace to overheat, shut off early and restart once it cools. A thermostat in direct sunlight or near a heat source can also trigger it, as can a dirty flame sensor that cannot detect the burner flame, which makes the furnace shut down as a safety measure. Blocked registers and duct obstructions can trip the furnace's safety shutoffs for similar reasons. If the filter and thermostat location check out, call for a professional diagnosis.

4. Bad odors, and which ones are urgent

Not every smell is an emergency. A burning-dust smell the first time you run the furnace each fall is normal and should fade quickly. A musty smell usually means an overdue filter or dirty, damp ducts. But two smells need immediate action. A chemical odor can point to a cracked heat exchanger, which can leak carbon monoxide into the house: leave the building and call for emergency service. A rotten-egg smell means a possible gas leak: turn off the gas if you can do so safely, leave right away and call your gas utility from outside.

5. Higher fuel or energy use

A furnace that struggles to hold temperature uses more fuel or electricity to do the same job. Typical causes include a dirty filter, neglected maintenance such as dusty burners and dirty flame sensors, an aging and inefficient furnace, a failing thermostat, or a failing blower motor, gas valve or ignition system. If your furnace is more than 15 years old, rising costs may be a sign to start planning for a replacement rather than putting more money into repairs.

Any of these signs deserves attention, and several of them are safety issues that should never be put off. Make sure you have working carbon monoxide detectors in the house, and do not keep running a furnace that bangs, smells like chemicals or shuts down repeatedly.

ACT Heat & Air repairs and services all makes and models of furnaces for homes and businesses in Yakima, Union Gap, Ellensburg, Prosser, Kennewick, Richland and Pasco. Call (509) 388-2997 to schedule a furnace inspection, or use our 24 hour emergency service if your heat goes out or you suspect a safety problem.